I never liked eating in restaurants alone until, when I was 28, the company I was working for transferred me to NYC. Part of the agreement was that I would have three months' worth of lodging and a $50 per day food allowance, too.
At that time I never ate more than an occasional muffin for breakfast and would have a sandwich delivered for lunch, which I'd pay for out of pocket and save the $50 for a decent dinner after work. There were plenty of times I'd wind up eating with someone but the majority of these meals were eaten alone in contented silence except for engaging the server about my order.
At least when I was in my career and making decent money, any time I ate out with someone inevitably involved my picking up the tab. Though I rarely resented it as such, I usually figured how much better I could have eaten, and for less money, too, had I eaten alone.